Heretofore, as disclosed in the following Patent Document 1, there has been known a vehicle front structure comprising a long-shaped frame member comprised of a front side frame disposed along a front-rear direction of a vehicle, wherein the frame member is formed with a front bendable portion and a rear bendable portion in two points spaced apart from each other in a longitudinal direction thereof, and wherein positions of the front and rear bendable portions are set to become different from each other in a width direction or an up-down direction of the frame member. In this conventional structure, when a load along the longitudinal direction of the frame member is input into the frame member, each of the front and rear bendable portions is compressively deformed, so that the frame member is buckled into a wavy shape. Thus, when the frame member undergoes deformation, for example, due to vehicle collision, it becomes possible to prevent the deformed frame member from interfering with an engine or the like, thereby desirably attenuating a load during the collision.
In the vehicle front structure disclosed in the Patent Document 1, the front side frame constituting the long frame member has a depressed section which is formed in a lower region of a vehicle-width directional inner portion thereof to have two ridge lines each with an upwardly-curved curve shape in a central region thereof, so that it is possible to ensure an installation space for a powertrain comprising an engine and a transaxle assembly disposed in a front of the vehicle. However, in the case where the depressed section having the upwardly-curved central region is formed in the lower region of the vehicle-width directional inner portion of the front side frame, a vehicle collision load is liable to act concentratedly on the depressed section of the front side frame, which causes a problem that it is difficult to avoid a situation where the front side frame is deformed in such a manner as to be largely bent on the basis of the depressed section.